Negativity bias is the tendency to focus on only those things that aren't working, rather than focusing on what has improved. I've observed that during a switch from one AMS to another, frequently staff will fall into this trap. The result can be as simple as spending too much time on trying to fix something that isn't that important, to the extreme of staff believing the entire implementation has failed.

True story: I once had an executive director tell me an AMS implementation I was assisting with was a "complete failure" (her words) because we had gone live with one piece of functionality still not working. In her mind, this proved the project had failed, even though everything else had launched properly and they had seen many significant improvements over the old system. (The punchline is that not only was the functionality fixed within weeks, but that "failed" system has been used by the association for over 12 years now!)

So our job is to make sure we communicate the successes that any given project has achieved, as frequently as possible. Humans have a tendency to focus on the negative and flat out forget the positives. So we have to help them re-focus by reminding them of everything that has improved.